The hamstring muscle group comprises three muscles: the semitendinosus, the semimembranosus, and the biceps femoris. The hamstring muscle group acts upon both the hip and knee joints. The hamstrings play an important role in walking, running, jumping, and controlling some movement of the trunk of the body.
Many people suffer from tightness of the hamstrings. Tightness of the hamstrings can be caused by genetic factors (some people are naturally born with shorter hamstring muscles), back problems can also cause the sciatic nerve to become compressed which can cause the hamstring muscles to tighten, and lack of stretching before physical activity can also cause tightness in the hamstring muscles. Furthermore, sedentary lifestyles and/or desk jobs that involve sitting for long periods of time can also contribute to tightness in the hamstring muscles.
Tightness in the hamstring muscles can cause decreased physical performance and can make the muscles more susceptible to tearing during physical activities. Furthermore, the tightness in the hamstring muscles can also lead to postural problems and/or back problems by causing the hips and/or the pelvis to rotate to position that can compress nerves and/or put strain on other muscle groups. Pain in the back and knees are also a common result.
Stretching of the back and hamstring muscles can increase flexibility and blood flow to these muscles groups and can help to alleviate pain and/or stiffness caused by tightening of the hamstring muscles.